TREASURY UNITS (Details)				12 Months Ended		161 Months Ended
	Mar. 09, 2020	Mar. 10, 2015 shares	Aug. 20, 2007 shares	Dec. 31, 2020 USD ($) $ / item shares	Dec. 31, 2019 USD ($) $ / item shares	Dec. 31, 2020 USD ($) $ / item shares	Mar. 09, 2015 shares
Treasury units				58,469		58,469
Period for repurchase of depository receipts	5 years	5 years	12 months
Depository receipts authorized to be repurchased		2,000,000	300,000				1,500,000
Depositary receipt as a percent of one Class A Unit			10.00%
Number of depository receipts repurchased						1,428,437
Repurchase price of depository receipts (in dollars per receipt) | $ / item						28.43
Units required to be repurchased (in shares)				222	2,408
Total cost of repurchase | $				$ 394,031	$ 4,050,137	$ 44,718,000
General Partnership
Treasury units				585		585
Fixed distribution percentage of unit holders	1.00%			1.00%
Number of depository receipts repurchased						188
Units required to be repurchased (in shares)				2.22	24.1
Total cost of repurchase | $				$ 3,941	$ 40,498
Treasury Units
Units required to be repurchased (in shares)				222	2,408
Class A
Fixed distribution percentage of unit holders	80.00%
Number of depository receipts repurchased				5,328	57,803
Repurchase price of depository receipts (in dollars per receipt) | $ / item				59.14	56.05	852.90
Repurchase price of units (in dollars per unit) | $ / item				1,774.20	1,681.50
Total cost of repurchase | $				$ 315,220	$ 3,240,181
Class B
Fixed distribution percentage of unit holders	19.00%
Number of depository receipts repurchased						3,572
Units required to be repurchased (in shares)				42.18	457.6
Total cost of repurchase | $				$ 74,870	$ 769,458
Class B and General Partnership Units
Repurchase price of depository receipts (in dollars per receipt) | $ / item						1,033.00
Class A
Treasury units				46,775		46,775
Class B
Treasury units				11,109		11,109
Fixed distribution percentage of unit holders				19.00%